372 Fritsch, Observations on the young, plants of Stigeoclonium Kütz. 
In species, however, in which the hairs are less strongly deve- 
loped, no indication of them is to be found in the young forms at 
all (cp. Tab. XI, figs. 18, 20); and only in the later stages do the 
ends of the br anches elongate and develop into hairs. Sig. varia- 
bile very frequently shows the type of young plant, figured on Tab. 
XI, fig. 18. The upright, 4—5 celled filaments are at this stage as 
yet unbranched; their somewhat acute apex is bent round in a curious 
fashion, so as to form a kind of hook. This bent portion later on 
develops into a hair. 
Branching usually commences at an’early stage, if the adult 
filaments are at all rich in branches (cp. the description just given 
of the germination of an undetermined Siigeoclonium). In sStig. 
nanum, which is very abundantly branched in the adult stage, this 
character soon becomes manifest in the young plant (Tab. XII, figs. 
26 at a and 29). Figs. 27 and 28 on Tab. XII however show that 
in some cases branching of the upright filaments does not become 
apparent so early. 
In the majority of cases a creeping basal portion is developed, 
usually arising in the species, which I examined, according to the 
first type of development, described by Berthold (ep. p. 22); in 
some cases, however, it originated previous to the formation of any 
upright filaments (Berthold’s second type). My investigation was 
concerned not so much with the development of the young plant, as 
with its ultimate structure, and the remarks that follow are there- 
fore confined to this latter point. 
The basal portion, corresponding to the „Sohle“ of Cienkowski, 
may attain a varied degree of development. In Sig. variable it 
does not usually reach any very considerable size. Apart from the 
fact, that this species frequently develops no basal portion whatever, 
(a point, which shall be discussed more fully immediately), this 
latter when present senerally only consists of from three to five 
cells (Tab. XI, figs. 17 and 20); as is shown by the figures the cells 
of this basal portion are in addition mostly dead and empty by the 
time the upright filaments are well developed. In Tab. XII figs. 30, 
31 and 32, all of Sig. variabıle, show that in some cases the basal 
portion may attain to more importance. In Fig. 30 it is 6-celled 
and slightly branched; from either end a rhizoid is developing and 
two upright filaments are being given off. In Fig. 31 the basal 
portion is 6-celled, whilst in Fig. 32 it is even 9-celled. In all these 
cases the cells of the base are still living and do not differ in any 
‘ way from those of the upright filaments, both being filled with large 
quantities of food-material. 
After these young plants of St. variable had been kept in doors 
for some weeks it was found, that the base, as well as the upright 
filaments, were encased in a thick, colourless mucilaginous sheath. 
This on either side of the filament reached a thickness, often exceed- 
ing the diameter of the cells. Although generally quite distinct 
without the application of any artificial agency, it stood out very 
clearly, when the young plants were placed in water, coloured dark 
brown by the addition of a few drops of Indian ink. The dark 
fluid was separated from the filaments by a colourless area of con- 
siderable width. The mucilage, enveloping the filaments, stained 
